1. Field of the Invention
The present invention relates generally to a rear axle supporting structure in a three-wheeled motor vehicle. More particularly, the invention relates to a rear axle supporting structure in a three-wheeled vehicle equipped with a chain drive mechanism.
2. Description of Relevant Art
In three-wheeled motor vehicles of the type in which two rear wheels are driven by a drive chain, especially in those of the type in which two rear wheels are rotatably supported at the rear end of a swing arm, the front end of which is vertically pivotably attached to the vehicle body frame, adjustment of the drive chain has been performed by moving the pivot center of the swing arm in the longitudinal direction relative to the vehicle body frame.
Such chain adjusting method is advantageous in that the structure of the support portion for the rear axle at the rear end of the swing arm is simplified and the unsprung weight is decreased. However, because the pivot centers at the fore ends of the right and left arm portions of the swing arm are adjusted separately, the adjusting operation is troublesome, and it has been difficult to select a proper positional mounting relation between the vehicle body frame and the right and left arm portions of the swing arm.
The present invention effectively overcomes such problems attendant the adjustment of a rear wheel driving chain in conventional three-wheeled motor vehicles equipped with a chain drive mechanism.